The use of flatbed trailers are well known for carrying various cargo behind a wheeled vehicle. A common variety of flatbed trailer includes ramp attachments at front and rear ends of the trailer for loading recreational vehicles thereon, including snowmobiles, personal all terrain vehicles and motorcycles. Often it is desirable to protect the equipment carried on the flatbed from the elements with a suitable cover.
U.S. Pat. No. 5,681,074 to Christensen and U.S. Pat. No. 6,488,329 to Smith disclose examples of flatbed trailers in which a cover is provided in the form of a domed shell which is pivoted on the flatbed deck at respective front or rear ends of the deck between respective open and closed positions. Covers for flatbed trailers are typically of this design, in which the cover is pivoted in the direction of travel of the vehicle either forwardly or rearwardly. Due to loading typically being in the same direction as the direction of travel, the cover limits the overhead clearance in the direction of loading. For example, a person sitting on a snowmobile typically has to duck as the vehicle is driven onto the flatbed deck of the trailer. When sitting on a personal all terrain vehicle, the operator would have to lay down on the seat to avoid collision with the prior art overhead covers, whereas a motorcycle operator typically cannot even sit on the vehicle due to the higher ride height and less stable configuration of the vehicle. Furthermore such one piece covers are typically heavy and awkward for a single operator to handle and thus two persons are usually required for loading unless a linkage is provided for assistance in lifting the cover. The linkages which assist in lifting such covers however provide further limitations to the amount of overhead clearance as the degree to which the cover can be lifted is further limited by the linkage. These prior one piece designs for covers are also readily susceptible to catching gusts of winds which may tear the cover from the flatbed causing considerable damage and possible harm to surrounding persons.
A further design of a cover for a flatbed trailer is illustrated in U.S. Design Patent 406,800 to Nece in which a frame is provided with an overhead beam spanning laterally across the trailer spaced above the deck. A front and rear cover are pivotally coupled to opposing front and rear sides of the overhead beam for pivotal movement in respective forward and rearward directions as the covers are opened. The overhead beam and forward and rearward pivotal movement of the overhead covers again provides limitations to overhead clearance when loading or unloading recreational vehicles and the like.